The Ukrainian Foreign Ministry has described the visit to Sevastopol by a Russian delegation headed by President Vladimir Putin as an act of defiance of international humanitarian law.
It said in a statement that Crimea and Sevastopol have been and will be an integral part of Ukraine within its internationally recognized borders.
A protest note to this effect was sent to the Russian Foreign Ministry.
Putin came to Sevastopol on 18 August to visit a new secondary school, according to the Kremlin website.
He was accompanied by Russian Prime Minister Dmitriy Medvedev, the president's representative to the Southern Federal District, Vladimir Ustinov, Education Minister Olga Vasilyeva and Sevastopol "governor" Dmitriy Ovsyannikov.